The present disclosure relates to a technique for controlling a motor.
Motor devices have recently become widespread which have a built-in driver IC for controlling the rotation of a motor. In such a motor device, a desired rotational speed of the motor can be obtained by simply inputting a speed command signal designating the rotational speed of the motor into the driver IC from outside the motor device. Therefore, the configuration for controlling the motor can be simplified.
The driver IC of the motor device generally includes a lock signal output circuit for outputting a lock signal. By referring to the lock signal output from the lock signal output circuit, it can be detected whether the motor is rotating or stopping.
However, the above motor device has a problem in that the load on the motor cannot be detected. Although whether the motor is rotating or stopping can be detected by reference to the lock signal, it cannot be detected that an excessive load has been imposed on the motor until the motor stops.
As a solution to this problem, a technique is known for detecting the output current of a motor drive section for driving a motor and determining the load on the motor based on the detected output current.